./toolbox
esthanres.pro

Last modification date:

Wed Sep 28 13:27:11 2016

esthanres

function esthanres(oldres)

Estimate the new frequency_resolution after hanning smoothing something with a known old frequency_resolution.

This estimates the new frequency_resolution by assuming that the frequeny_resolution is the FWHM of a gaussian response function and that the ratio of the widths is equal to the inverse ratio of the heights of the response functions before and after the smoothing. Since a hanning function isn't a Gaussian, this will be inaccurate to some degree. The initial response function may also not be Gaussian. Tests against a full convolution as well as tests involving noise from real GBT data indicate that this estimate is accurate to within a few percent.

The hanning procedure uses this function to adjust the frequency_resolution of the data container.

Returns

the frequency resolution in channels after hanning smoothing.

Examples

   ; what would the new resolution be of the PDC after hanning
   ; smoothing
   print,

   esthanres(!g.s[0].frequency_resolution/abs(!g.s[0].frequency_interval))
 

Uses

gaussrespfn

Version

$Id$

Parameters
oldres in, required float	The frequency_resolution in channels before hanning smoothing.